Small arm

ABSTRACT

A barrel is fixed in a barrel-carrying member and provided on its outside peripheral surface with a piston and formed with transverse bore means, which communicate with the inside of the barrel and open on the outside peripheral surface thereof forwardly of said piston. An action slide comprises a cylinder, which is spaced around said barrel and defines therewith an annular chamber, which is sealed by said piston and is defined by flow-obstructing means spaced from said piston beyond said transverse bore means. The action slide is capable of a recoil movement relative to said barrel so as to decrease the size of said annular chamber. A counter-recoil spring cooperates with said action slide and tends to move said action slide opposite to the direction of said recoil movement.

United States Patent Kepplinger et al. 1 1 June 3, 1975 SMALL ARMgvilshon ..I .1 8945199192 i -m" eta. [75] inventors: Hannes Kepplinger:Karl Wagner, at b )th )f Ste 'r. Austria L t Primary lzxummer-Stephen C.Bentley i 1 Assigneei steyr'naimler'puch Armrney, Agent. or Firml(urtKelman Aktiengesellschaft, Vienna, Austria [22] Filed: Nov. 30, 1973 57ABSTRACT pPl. O: 20,539 A barrel is fixed in a barrel'carrying memberand provided on its outside peripheral surface with a piston [30]Foreign Application Priority Data and formed with transverse bore means,which com- D 6 [977 A Imam/77 municate with the inside of the barrel andopen on the it 9071/7; outside peripheral surface thereof forwardly ofsaid Ausm piston. An action slide comprises a cylinder. which is spacedaround said barrel and defines therewith an an 2% 'i 89/191 gf i ignular chamber, which is sealed by said piston and is i 193 180 definedby flow-obstructing means spaced from said L 1 le 0 earc 2 6 pistonbeyond said transverse bore means. The action slide is capable of arecoil movement relative to said s6 R f Ct d barrel so as to decreasethe size of said annular cham- L l e erences le her. A counter-recoilspring cooperates with said ac- UNITED STATES PATENTS tion slide andtends to move said action slide opposite 1.834.021 12/1931 Destree89/191 R t the direction of said recoil movement. 2.340.293 2/1944Balleisen 89/193 3,018,694 1/1962 Browning 89/193 6 Claims, 3 DrawingFigures SMALL ARM This invention relates to a small arm, particularly toa pistol, having a grip or the like, a barrel firmly inserted in thegrip or the like, and an action slide, which has a forward portionsurrounding the barrel and is adapted to be pushed back against acounterrecoil spring and cannot be locked to the barrel.

These small arms have the advantage of being particularly simple inconstruction because there is no locking mechanism between the barreland the action slide. Besides, the fact that the barrel is rigidlyinserted in the grip or the like increases the accuracy of the shootingbecause the barrel is rigidly connected to the grip or the like andthere is no backlash which even though small would be essential inconnection with a movable barrel. On the other hand, such arm can beused in practice only if the propelling force of the gases produced bythe powder, the mass of the action slide, and the force of thecounterrecoil spring are matched. In case ofa larger caliber or anincreased propelling force of the gases produced by the powder, the massof the action slide must be increased and, because the kinetic energy ofthe action slide increases as the square of velocity, the force of thecounterrecoil spring must be considerably increased. Because there arelimits to the overall weight and overall dimensions of the arm, the massof the action slide can hardly be increased if the arm should remainhandy. The increase of the force of the counterrecoil spring is closelylimited because it must be possible to cock the arm by hand. For thisreason, designs embodying a strict mass-controlled action slide havebeen used so far only with small-caliber arms.

So-called gas-operated firearms are known, in which the barrel has atleast one transverse bore, which is connected by a passage to a piston.When the shot is fired, the action slide is locked to the barrel. Afterthe shot, the gases from the powder flow to the piston and act on thepiston to release the lock. Compared to the arm having a mass-controlledaction slide, this design is complicated and involves a high structuralexpenditure.

It is an object of the invention to eliminate these disadvantages and toprovide a small arm, particularly a pistol, which is of the kinddescribed first hereinbefore and which is suitable also for relativelylarge calibers and high gas pressures without substantial increase instructural expenditure and without need for an excessively strongcounterrecoil spring.

This object is accomplished according to the invention in that thatportion of the action slide which surrounds the barrel serves as abarrel, which confines an annular chamber, which is sealed at thebarrel, that the barrel forms a piston adjacent to the rear end of thecylinder and is formed with at least one transverse bore, which opensinto the annular chamber. Because the ac tion slide recoils after theshot has been fired, the cylinder which surrounds the barrel and formspart of the action slide is moved relative to the barrel so that theannular chamber disposed forwardly of the piston is reduced in size. Assoon as the bullet forced through the barrel when the shot has beenfired has moved past the transverse bore or transverse bores, theexpanding gases produced by the powder enter through the transverse boreor transverse bores the annular chamber, which during the recoil of theaction slide has been decreased in size because the piston has remainedin position. As a result, the rearward movement of the action slide isstrongly braked, and the recoil spring need no longer take up the fullkinetic energy of the action slide. For a larger caliber, it is nolonger necessary to increase the mass of the action slide, and arelatively weak counterrecoil spring is sufficient, which can readily becocked by hand.

According to a further feature of the invention, the cylinder whichsurrounds the barrel consists of a separate member, which is detachablylocked to the remainder of the action slide by a bayonet lock and isadapted to be locked in locking position by the counterrecoil spring.This division affords advantages in manufacture and facilitates thecleaning of the cylinder which receives the powder gases. In a desirablemanner, the counterrecoil spring is also utilized to hold the 7 cylindermember in its locked position.

To ensure a good sealing of the annular chamber at the rear even in thepresence of incrustations due to powder residues on the inside surfaceof the cylinder, the piston formed on the barrel consists in accordancewith the invention of two collars, and piston rings dis posed betweenthe collars.

It has been found that cartridges of the same caliber but of differentorigin may differ in propelling charge and in weight. If the arm weredesigned only for cartridges of one kind, the firing of more or lesspowerful cartridges would result in an excessive reaction or even introuble regarding the recoil of the action slide. According to theinvention, the cylinder which surrounds the barrel carries for thisreason adjacent to the muzzle a guide bushing which has been insertedfrom the forward end of the cylinder and seals the forward end of theannular chamber and can be selectively replaced by a guide bushing whichdefines at least one flow passage.

The arrangement of the bores, the size of the cylinder chamber and thedimensions of the counterrecoil spring are suitably selected with a viewto the cartridges of the most powerful kind to be used. When it isdesired to use less powerful cartridges, the braking action of thepowder gases in the annular chamber may be so strong that the completerecoil movement of the action slide is no longer ensured in spite of thereduced reaction. A shorter recoil movement of the action slide willresult in functional disturbances as regards the ejection of the case ofthe cartridge which has been fired and the feeding of the nextcartridge. In this case, the bushing is replaced by the alternative one,which is provided according to the invention and has at least one flowpassage, through which part of the powder gases produced by the powderand entering the annular chamber can escape so that the braking force isreduced to such an extent that the complete recoil movement of theaction slide is ensured. It will be sufficient if the user of the pistolascertains the ballistic data which appear on each cartridge package andif he selects that guide bushing which is proper in view of these dataand inserts said guide bushing into the cylinder. The guide bushingensures a good guidance of the cylinder on the barrel and constitutes anintegral sealing member, which can easily be inserted and removed.Besides, the cylinder may be provided with a continuous bore so that itcan be cleaned more easily.

lt will also be desirable to provide the barrel on its outside withrecesses, which extend from the transverse bore or bores toward themuzzle and taper in this direction to ensure an improved deflection ofthe powder gases into the longitudinal direction of the barrel as theyexit from the transverse bore.

An embodiment of the invention is shown by way of example on theaccompanying drawing. in which FIGS. 1 and 2 are, respectively, alongitudinal sec tional view and a transverse sectional view taken online lIII of FIG. 1 and showing a pistol.

FIG. 3 is a forward elevation showing an alternative guide bushing.

The barrel 1 of the pistol is immovably fixed in the grip 2, which isshown only in part. The action slide 3 is slidably guided on the grip 2and consists of a socalled mass-controlled action slide, which is notlocked to the barrel 1 even when the shot is fired. The body of theaction slide 3 extends forwardly as far as to the muzzle and is lockedthere to a cylinder 5, which surrounds the barrel 1 so as to definetherewith an annular chamber 4. The connection between the body of theaction slide 3 and the cylinder 5 is established in the usual manner bya bayonet joint, of which only a locking boss 6 is shown (FIG. 1). Thecylinder 5 is held in the locked position by a counterrecoil spring 7,which is associated with the action slide 3. The enlarged end portion 8of the cylinder 4 is provided in its rear end face with a recess 9, anda locking member 10 is provided, which under the action of thecounterrecoil spring snaps into the recess 9. To separate the cylinder 5from the body of the action slide 3, it will be sufficient to force thelocking member 10 back by hand against the force of the counterrecoilspring 7 until the locking member 10 leaves the recess 9. Thereafter itwill be sufficient to rotate the cylinder 5 relative to the body 3 ofthe action slide. it will be understood that it is the main function ofthe counterrecoil spring 7 to return the action slide 3 to its closedposition when it has recoiled as the shot was fired.

Adjacent to the rear end of the cylinder 5, the barrel 1 consists of apiston, which comprises two collars 11 and three piston rings 12disposed between said collars. The barrel 1 is provided with fourtransverse bores 13, which open into the annular chamber 4, and isformed with recesses 14, which extend from respective transverse bores13 toward the muzzle and taper in this direction.

Adjacent to the muzzle, a guide bushing 15 is provided, which has beenscrewed into the cylinder 5, more particularly into its end portion 8,from the forward end thereof and which seals the annular chamber 4 atits forward end. Two milled flats 16 are provided for engagement by atool by which the guide bushing 15 can be screwed in and out moreeasily.

When the shot has been fired and the bullet has moved past thetransverse bores 13, the gases produced by the powder enter the annularchamber 4 as the same is decreased in size because the cylinder 5follows the recoil movement of the body of the action slide 3 whereasthe piston formed by the collars 11 on the barre] 1 remains in position.As a result, the gases produced by the powders brake the recoil movementof the action slide until the bullet has left the barrel 1 and the gasesproduced by the powders can escape through the transverse bores 13 andthe barrel bore.

When it is desired to fire less powerful cartridges, the guide bushing15 is replaced by a guide bushing (FIG. 3), which has a bore that isenlarged at three points so that said bore and the outside peripheralsurface of the barrel 1 define flow passages 17 for the gases producedby the powder. Alternatively, the flow passages may consist of finebores in the end wall of the guide bushing 115. It will be essentialthat part of the gases produced by the powder can escape forwardly fromthe annular chamber 4 so that the braking force will be reduced whereless powerful cartridges are fired and a complete recoil movement of theaction slide member 3 will be ensured in such case too.

What is claimed is:

1. A small arm, which comprises a barrel-carrying member,

a barrel fixed in said barrel-carrying member and provided on itsoutside peripheral surface with a piston and formed with transverse boremeans, which communicate with the inside of the barrel and open on theoutside peripheral surface thereof before said piston, said outsideperipheral surface being formed with recess means which extend and taperforwardly from said transverse bore means,

an action slide which comprises a cylinder, which is spaced around saidbarrel and defines therewith an annular chamber, which is sealed by saidpiston and defined by flow-obstructing means spaced from said pistonbeyond said transverse bore means, said action slide being capable of arecoil movement relative to said barrel so as to decrease the size ofsaid annular chamber, and

a counterrecoil spring, which cooperates with said action slide andtends to move said action slide opposite to the direction of said recoilmovement.

2. A small arm as set forth in claim 1, in which said transverse boremeans consist of a plurality of transverse bores.

3. A small arm as set forth in claim 1, in which said action slidecomprises a second member and bayonet joint means detachably lockingsaid second member to said cylinder and said counterrecoil spring isarranged to hold said cylinder in position relative to said secondmember.

4. A small arm as set forth in claim 1, in which said piston consists oftwo axially spaced apart collars and of piston ring means disposedbetween said collars.

5. A small arm as set forth in claim 1, in which said barrel has amuzzle and said flow-obstructing means comprise a detachable guidebushing, which surrounds said barrel adjacent to said muzzle and hasbeen inserted into said cylinder from its forward end and seals saidannular chamber at its forward end.

6. A small arm as set forth in claim 1, in which said barrel has amuzzle and said flow-obstructing means comprise a detachable guidebushing, which surrounds said barrel adjacent to said muzzle and hasbeen inserted into said cylinder from its forward end and defines atleast one constricted flow passage with said barrel.

1. A small arm, which comprises a barrel-carrying member, a barrel fixedin said barrel-carrying member and provided on its outside peripheralsurface with a piston and formed with transverse bore means, whichcommunicate with the inside of the barrel and open on the outsideperipheral surface thereof before said piston, said outside peripheralsurface being formed with recess means which extend and taper forwardlyfrom said transverse bore means, an action slide which comprises acylinder, which is spaced around said barrel and defines therewith anannular chamber, which is sealed by said piston and defined byflow-obstructing means spaced from said piston beyond said transversebore means, said action slide being capable of a recoil movementrelative to said barrel so as to decrease the size of said annularchamber, and a counterrecoil spring, which cooperates with said actionslide and tends to move said action slide opposite to the direction ofsaid recoil movement.
 1. A small arm, which comprises a barrel-carryingmember, a barrel fixed in said barrel-carrying member and provided onits outside peripheral surface with a piston and formed with transversebore means, which communicate with the inside of the barrel and open onthe outside peripheral surface thereof before said piston, said outsideperipheral surface being formed with recess means which extend and taperforwardly from said transverse bore means, an action slide whichcomprises a cylinder, which is spaced around said barrel and definestherewith an annular chamber, which is sealed by said piston and definedby flow-obstructing means spaced from said piston beyond said transversebore means, said action slide being capable of a recoil movementrelative to said barrel so as to decrease the size of said annularchamber, and a counterrecoil spring, which cooperates with said actionslide and tends to move said action slide opposite to the direction ofsaid recoil movement.
 2. A small arm as set forth in claim 1, in whichsaid transverse bore means consist of a plurality of transverse bores.3. A small arm as set forth in claim 1, in which said action slidecomprises a second member and bayonet joint means detachably lockingsaid second member to said cylinder and said counterrecoil spring isarranged to hold said cylinder in position relative to said secondmember.
 4. A small arm as set forth in claim 1, in which said pistonconsists of two axially spaced apart collars and of piston ring meansdisposed between said collars.
 5. A small arm as set forth in claim 1,in which said barrel has a muzzle and said flow-obstructing meanscomprise a detachable guide bushing, which surrounds said barreladjacent to said muzzle and has been inserted into said cylinder fromits forward end and seals said annular chamber at its forward end.